public class Test_Frock {
    public static void main(String[] args) {
        Frock n1 = new Frock();
        Frock n2 = new Frock();
        Frock n3 = new Frock();
        System.out.println(n1.getSerialNumber());
        System.out.println(n2.getSerialNumber());
        System.out.println(n3.getSerialNumber());
    }
}
